A square has 4 right angels and 4 sides with equal angels ;)
Answer:
50 nickels, 20 quarters.
Step-by-step explanation:
System of equations (q = # of quarters, n = # of nickels):
<em>q + n = 70, 0.25q + 0.05n = 7.50</em>
the first equation can be changed to q = 70 - n, so we are able to <em>substitute q with 70 - n</em>.
So, it will look like <em>0.25*70 - 0.25n + 0.05n = 7.50</em>. This can be simplified to <em>0.2n = 10</em>, which means that n = 50.
Knowing that we can solve <em>q + 50 = 70</em>, which means that q = 20.
Check the picture below. Recall, is an open-top box, so, the top is not part of the surface area, of the 300 cm². Also, recall, the base is a square, thus, length = width = x.

so.. that'd be the V(x) for such box, now, where is the maximum point at?

now, let's check if it's a maximum point at 10, by doing a first-derivative test on it. Check the second picture below.
so, the volume will then be at
Assuming the vertex of the triangle shown is the center of the pentagon, and the line segment shown is an altitude of the triangle:
If we join the center of (the circumscribed circle and of) the pentagon to the 5 vertices, 5 isosceles triangles are formed, all congruent to the one shown in the figure. It is clear that these triangles are congruent, so to find the area of the pentagon, we find the area of one of these triangles and multiply by 5.
The base of the triangle is 22.3 in, and the height is 15.4 ins, thus the area of the pentagon is:
5(Area triangle)=5*[(22.3*15.4)/2]=<span>858.55 (square inches).
Answer: </span>858.55 (square inches).
Let t=number of years since 1991.
Then
P(t)=147 e^(kt) ... in millions
P(0)=147 e^(0)=147
P(7)=147 e^(7k)=153
e^(7k)=(153/147)
take ln both sides
ln(e^(7k))=ln(153/147)
7k=0.0400 => k=0.005715
Year 2017=>t=2017-1991=26
P(26)=147e^(26*.005715)=170.55
Answer: in 2017, the projected population is 170.55 millions.